Loss of power after high rpm's

[TexasDav]

I have run into a problem. My motor has 300+ miles and I have repaired just about every problem those motors have out of the box. Air leak, fouled plug, bad wire, fuel hose.

The problem now is. It has been consistaint and seemed to be broke in and smooth at 23 mph. This week it suddenly run up to 30 mph at top end, but if I go 30mph it then losses power and slowly dies. I was content with 23mph because the bike is heavy and so am I. plus it seems to have more vibration then it did. The plug is brown. and new plug had no effect. Fuel flows good to the carb. It seems to be caused by the excessive vibration. I went to a 32 to1 mix from the 20 to 1 break in mix. Should I go back to 20 to 1?

 

[Dave31]

Check your motor mounts...If they are a little lose/broke it will cause a small vibration and the motor will fall flat on it's face. Thier is a thread on it somewhere?

 

[Bikeguy Joe]

Yes, the fuel will foam causing it to lean out, sag, then recover if you let off or it slows enough.

Mount the engine in lead. http://motorbicycling.com/search.php?searchid=99593

 

[TexasDav]

that makes sense. I will see if I can reduce the vibration. Motor mounts or just not run too fast. Thanks for the quick advice.

 

[shane patterson]

hi i have a similer problem but i was just wondering if i just need new rings as i got a new cns carby and my 48cc engine toped 50 kph and then onday i was rinding it and it just lost power and now only hits 42 kph and virbtats alot when you hit 40 kph any iders thanks

 

[Bikeguy Joe]

hi i have a similer problem but i was just wondering if i just need new rings as i got a new cns carby and my 48cc engine toped 50 kph and then onday i was rinding it and it just lost power and now only hits 42 kph and virbtats alot when you hit 40 kph any iders thanks

Did your problem start after you mounted the new carb?

 

[shane patterson]

no it was going 50 kph when i put the carby on it was only going 40 kph whith the old carby